The Stovebolt Site Forums The Shop Area Driveline 1959 Mystery grumble and vibration

59 3/4 ton 4spd 235:
I've got a intermittent grumble, sounds like a bunch of rock tumbling together. I can feel a significant vibration on the floor board and all three pedals when this happens. No vibration in steering wheel.
It can happen at any speed or rpm, with clutch engaged or disengaged and in any gear or neutral.
There is no noticeable driveability change when the grumble occurs. The truck idles, accelerates, drives and shifts just fine while it's grumbling and vibrating. I thought it might be the clutch and recently replaced the clutch, pressure plate, throw out bearing, and had the flywheel resurfaced. The truck had the grumble before the clutch change and still has it. I did a cursory inspection of transmission. Output shaft was solid with no slop or play in it. I did not open up the transmission. U-joints were good with no play in them. Engine runs great with good oil pressure. The grumble and vibration always go away once the truck has come to a complete stop.
Because it's intermittent and won't happen with the truck stopped, I've have difficulty diagnosing it. My second guess after the clutch is something in the transmission. I cannot recreate the problem on demand. It comes and goes at any time. It usually on lasts a few seconds before it just goes away while driving or I come to a stop. Any ideas? Thank you in advance for your replies.

Does the grumble increase/decrease with speed? My first thought is a bad wheel bearing. Can you tell if the noise is in the front or rear of the truck? I'd suggest putting it on jack stands and rotate the wheels individually and see if it's a bearing. Then put it in gear and rotate the rear wheels and see if it's coming from the chunk or transmission. If that does't tell you anything, start the truck, put it in gear and let it turn the wheels and see if you can isolate the noise that way. I recommend a 2nd person to help and be a safety observer during this step.

I had the same problem on a '66 Olds 442. Turned out I had twisted the drive shaft (too much grip not enough slip) thus causing the bearings in the tail shaft of the transmission to shake apart.

Thanks for your responses guys. The grumble doesn't increase or decrease with speed. The noise and vibration seem to be coming from below my feet but I know that apparent noise location can be deceiving at times. The wheel bearings have been replaced/inspected recently and are in good shape. I cannot recreate the noise with the truck on jack stands with the tests you outlined or any other tests I've tried.
Sometimes when it happens in gear, I'll put it in neutral and coast to a stop. The grumble will stay constant in or out of gear and will continue until the truck comes to a complete stop. At a complete stops the grumble always goes away but it will grumble right up until a complete stop. The I'll put it into gear and start of again and it may or may not come back.
I drove it today for six miles and it only happened once from a stop and then disappeared after a few seconds.
I'm thinking it's something in the transmission but it's the intermittent nature of it that has me scratching my head.
James

Front universal joint. Jeffrey

Did you also look at the rear end? Pinion and/or axles bearings? You have a good mystery on your hands.

SimS

I had the same problem after repacking my wheel bearings about a year ago. You mentioned that yours had recently been replaced. Turns out that I did not tighten the left front one correctly and I had the exact problem that you describe. The noise didn't start until a couple months after I had repacked the bearings. You might want to check your front wheel bearings just to be sure and adjust if necessary. For me, it was a simple (but dumb) mistake that was easily fixed.

Matt

I checked the front wheel bearings today. They castle nuts were snug. I couldn't tighten them up to the next notch without really reefing on the nuts with a socket and breaker bar, so I left them as they were. There was no slop or play in the front wheels, side to side or back to back.
This intermittent grumble comes with a significant vibration in the truck. However, I don't feel the vibration in the steering wheel or stick shift. It is more a general vibration through the whole truck.
I will check the u-joints next but inspection of them a few months ago show no signs of wear or play.
The transmission shifts fine with or without the vibration. Steering is fine, brakes work great. Nothing seems loose underneath like the driveline mounts or anything else. What would cause the truck to vibrate like this intermittently in any gear or neutral, at any speed, and it comes and goes just like the wind. The truck does have to be rolling though. One more clue, the vibration doesn't increase or decrease when the car slows down. It stays constant in noise and vibration right up until the truck comes to a complete stop, and then the vibration/noise stops suddenly, almost as if on a switch.
James

Just food for thought, do you have a 2 piece driveshaft? If so maybe the carrier bearing is bad. Just a thought.

To check the front wheel bearings involves removing,
cleaning and inspecting the bearings. There should be no
rough spots when turning or visible pitting on the
rollers/balls and the races.

Checking castle nut tightness and wheel play only checks
bearing installation it does not verify bearing condition.
Jeffrey

Tommy,
I do have a two piece driveshaft. So I crawled under today and checked the bearing and there was excessive play in it. So I've ordered a new one. If the part arrives I'll get to it over the weekend and will let you know. Thanks for you thought!
Jeffrey,
As I said in my second post, "The wheel bearings have been replaced/inspected recently and are in good shape". So I appreciate your input and have already done the cleaning and inspection as you suggest. Matt had suggested I check their tightness just for good measure because he had had that problem in the past.
Thanks to all,
James

I tried removing the old central bearing today. There is a small metal collar on the driveshaft that sit close to backside of the bearing. It doesn't spin with the bearing. It is a separate piece. It isn't coming off of the driveshaft easily. I don't know if the collar is pressed on, or maybe has some clip holding it in place, or is maybe just rusted on. I didn't notice any obvious sign of a clip on anything holding the collar in place. It looks like once I get this collar off, the bearing will slide right of behind it.
Any ideas how to get the collar off?
Thank you,
James

The collar can make it a nuisance to change the carrier bearing if everything doesn't cooperate. I'm pretty sure that the collar is 'permanently' attached to the propshaft. It makes it hard to change the carrier bearing under the truck if the carrier bearing is stubborn. A simple task becomes harder.

Last one I did required me to put the propshaft in my bench vice and very carefully remove the old carrier bearing using a combination of an angle grinder, Dremel cut-off wheel and a cold chisel. I had to cut the old carrier bearing off the shaft. It's trash anyway, but it was a pain to get off. Don't damage or cut the prop shaft or the collar. The new carrier bearing slid right one and reassembly was easy.

I'm not sure what the purpose of the collar is other than to be a dust and rain shield, but I figured that if GM put it there, it must be there for a reason.

Most old propshafts that I see in salvage yards have dented or mangled collars. You aren't the first one experiencing the joy!

Matt

Matt,
There are two collars that surround the bearing on this two-piece driveshaft. There is a larger one in front of the bearing that is welded to the driveshaft. Also, the driveshaft diameter in front of this large collar is so thick that even without the collar, there is no way a new bearing could be installed from the front.

My problem is with a small collar directly behind the bearing. It is smaller in diameter than the bearing itself.

It looks to me that installing the bearing from the rear end of this driveshaft is the only way possible, but I can't get that small collar off. I could try cutting it off but I can't even tell how it's attached to the driveshaft and then of course I wouldn't be able to reuse it.
The bearing itself, in what very little room it has between the two collars, seems to slide up and down the driveshaft easily, so that I'm thinking it will slide off easily once I address the collar.
Any ideas would be appreciated.
James

Maybe time to go to a driveshaft shop.
Jeffrey

James, the front collar is the one that I was talking about. You are correct that the carrier bearing installs from the back. I had the same issue. A collar from the bearing had frozen itself to the propshaft. That's why I carefully cut it off. I think I have a spare front propshaft in my spare parts stash. I'll take a look later today or tomorrow to see if I can take some pix to explain it better.

Matt

James, I took some pix while at a salvage yard today. I used the title caption to label each picture.

If this is what yours looks like...what you are referring to as the back collar is actually a piece of the carrier bearing that came loose and froze to the propshaft. It needs to be cut off carefully to replace the carrier bearing. On this one, the carrier bearing was so bad that I couldn't get it to budge either, so it would also have to be carefully cut off. Use an angle grinder for the heavy work, remove what you can in pieces, then switch to a Dremel and chisel for the finesse work when you get close to the shaft. Working around the front collar will probably present a challenge to avoid cutting into it. Just be careful and you should be fine.

http://s844.photobucket.com/user/ma...2449_zpsfuhlsppk.jpg.html?sort=3&o=2

Hope this helps,

Matt

Nice pics!!!

Matt,
Thanks for the photos!
Good news: I did get the rear collar and the old bearing off. I soaked the collar in penetrating oil for five days and then with the help of a sturdy vice and a big pipe wrench I was able to finally rotate the collar on the shaft. Then with a punch and a hammer I was able to slowly hammer it off. I got lucky and no cutting was necessary. The bearing itself then slide right off.
I installed the new bearing and cleaned up and reused the rear collar.
The truck is no longer making the grumble or vibration!
So thanks to Tommy for the idea of checking the bearing and to Matt for helping me through removal process. Thanks to all of you who replied with your suggestions and advice. Mission accomplished.
Next up, new door weatherstripping from Steele Products.
James